/*
 * Title:        CloudSim Toolkit
 * Description:  CloudSim (Cloud Simulation) Toolkit for Modeling and Simulation of Clouds
 * Licence:      GPL - http://www.gnu.org/copyleft/gpl.html
 *
 * Copyright (c) 2009-2012, The University of Melbourne, Australia
 */

package cloudsim;

import cloudsim.network.datacenter.NetworkCloudletSpaceSharedScheduler;

import java.util.ArrayList;
import java.util.List;


/**
 * CloudletScheduler is an abstract class that represents the policy of scheduling performed by a
 * virtual machine to run its {@link Cloudlet Cloudlets}.
 * So, classes extending this must execute Cloudlets. Also, the interface for
 * cloudlet management is also implemented in this class.
 * Each VM has to have its own instance of a CloudletScheduler.
 *
 * @author Rodrigo N. Calheiros
 * @author Anton Beloglazov
 * @since CloudSim Toolkit 1.0
 */
public abstract class CloudletScheduler {

    /**
     * The previous time.
     */
    private double previousTime;

    /**
     * The list of current mips share available for the VM using the scheduler.
     */
    private List<Double> currentMipsShare;

    /**
     * The list of cloudlet waiting to be executed on the VM.
     */
    protected List<? extends ResCloudlet> cloudletWaitingList;

    /**
     * The list of cloudlets being executed on the VM.
     */
    protected List<? extends ResCloudlet> cloudletExecList;

    /**
     * The list of paused cloudlets.
     */
    protected List<? extends ResCloudlet> cloudletPausedList;

    /**
     * The list of finished cloudlets.
     */
    protected List<? extends ResCloudlet> cloudletFinishedList;

    /**
     * The list of failed cloudlets.
     */
    protected List<? extends ResCloudlet> cloudletFailedList;

    /**
     * Creates a new CloudletScheduler object.
     * A CloudletScheduler must be created before starting the actual simulation.
     *
     * @pre $none
     * @post $none
     */
    public CloudletScheduler() {
        setPreviousTime(0.0);
        cloudletWaitingList = new ArrayList<ResCloudlet>();
        cloudletExecList = new ArrayList<ResCloudlet>();
        cloudletPausedList = new ArrayList<ResCloudlet>();
        cloudletFinishedList = new ArrayList<ResCloudlet>();
        cloudletFailedList = new ArrayList<ResCloudlet>();
    }

    /**
     * Updates the processing of cloudlets running under management of this scheduler.
     *
     * @param currentTime current simulation time
     * @param mipsShare   list with MIPS share of each Pe available to the scheduler
     * @return the predicted completion time of the earliest finishing cloudlet,
     * or 0 if there is no next events
     * @pre currentTime >= 0
     * @post $none
     */
    public abstract double updateVmProcessing(double currentTime, List<Double> mipsShare);

    /**
     * Receives an cloudlet to be executed in the VM managed by this scheduler.
     *
     * @param gl               the submited cloudlet (@todo it's a strange param name)
     * @param fileTransferTime time required to move the required files from the SAN to the VM
     * @return expected finish time of this cloudlet, or 0 if it is in a waiting queue
     * @pre gl != null
     * @post $none
     */
    public abstract double cloudletSubmit(Cloudlet gl, double fileTransferTime);

    /**
     * Receives an cloudlet to be executed in the VM managed by this scheduler.
     *
     * @param gl the submited cloudlet
     * @return expected finish time of this cloudlet, or 0 if it is in a waiting queue
     * @pre gl != null
     * @post $none
     */
    public abstract double cloudletSubmit(Cloudlet gl);

    /**
     * Cancels execution of a cloudlet.
     *
     * @param clId ID of the cloudlet being canceled
     * @return the canceled cloudlet, $null if not found
     * @pre $none
     * @post $none
     */
    public abstract Cloudlet cloudletCancel(int clId);

    /**
     * Pauses execution of a cloudlet.
     *
     * @param clId ID of the cloudlet being paused
     * @return $true if cloudlet paused, $false otherwise
     * @pre $none
     * @post $none
     */
    public abstract boolean cloudletPause(int clId);

    /**
     * Resumes execution of a paused cloudlet.
     *
     * @param clId ID of the cloudlet being resumed
     * @return expected finish time of the cloudlet, 0.0 if queued
     * @pre $none
     * @post $none
     */
    public abstract double cloudletResume(int clId);

    /**
     * Processes a finished cloudlet.
     *
     * @param rcl finished cloudlet
     * @pre rgl != $null
     * @post $none
     */
    public abstract void cloudletFinish(ResCloudlet rcl);

    /**
     * Gets the status of a cloudlet.
     *
     * @param clId ID of the cloudlet
     * @return status of the cloudlet, -1 if cloudlet not found
     * @pre $none
     * @post $none
     * @todo cloudlet status should be an enum
     */
    public abstract int getCloudletStatus(int clId);

    /**
     * Informs if there is any cloudlet that finished to execute in the VM managed by this scheduler.
     *
     * @return $true if there is at least one finished cloudlet; $false otherwise
     * @pre $none
     * @post $none
     * @todo the method name would be isThereFinishedCloudlets to be clearer
     */
    public abstract boolean isFinishedCloudlets();

    /**
     * Returns the next cloudlet in the finished list.
     *
     * @return a finished cloudlet or $null if the respective list is empty
     * @pre $none
     * @post $none
     */
    public abstract Cloudlet getNextFinishedCloudlet();

    /**
     * Returns the number of cloudlets running in the virtual machine.
     *
     * @return number of cloudlets running
     * @pre $none
     * @post $none
     */
    public abstract int runningCloudlets();

    /**
     * Returns one cloudlet to migrate to another vm.
     *
     * @return one running cloudlet
     * @pre $none
     * @post $none
     */
    public abstract Cloudlet migrateCloudlet();

    /**
     * Gets total CPU utilization percentage of all cloudlets, according to CPU UtilizationModel of
     * each one.
     *
     * @param time the time to get the current CPU utilization
     * @return total utilization
     */
    public abstract double getTotalUtilizationOfCpu(double time);

    /**
     * Gets the current requested mips.
     *
     * @return the current mips
     */
    public abstract List<Double> getCurrentRequestedMips();

    /**
     * Gets the total current available mips for the Cloudlet.
     *
     * @param rcl       the rcl
     * @param mipsShare the mips share
     * @return the total current mips
     * @todo In fact, this method is returning different data depending
     * of the subclass. It is expected that the way the method use to compute
     * the resulting value can be different in every subclass,
     * but is not supposed that each subclass returns a complete different
     * result for the same method of the superclass.
     * In some class such as {@link NetworkCloudletSpaceSharedScheduler},
     * the method returns the average MIPS for the available PEs,
     * in other classes such as {@link CloudletSchedulerDynamicWorkload} it returns
     * the MIPS' sum of all PEs.
     */
    public abstract double getTotalCurrentAvailableMipsForCloudlet(ResCloudlet rcl, List<Double> mipsShare);

    /**
     * Gets the total current requested mips for a given cloudlet.
     *
     * @param rcl  the rcl
     * @param time the time
     * @return the total current requested mips for the given cloudlet
     */
    public abstract double getTotalCurrentRequestedMipsForCloudlet(ResCloudlet rcl, double time);

    /**
     * Gets the total current allocated mips for cloudlet.
     *
     * @param rcl  the rcl
     * @param time the time
     * @return the total current allocated mips for cloudlet
     */
    public abstract double getTotalCurrentAllocatedMipsForCloudlet(ResCloudlet rcl, double time);

    /**
     * Gets the current requested ram.
     *
     * @return the current requested ram
     */
    public abstract double getCurrentRequestedUtilizationOfRam();

    /**
     * Gets the current requested bw.
     *
     * @return the current requested bw
     */
    public abstract double getCurrentRequestedUtilizationOfBw();

    /**
     * Gets the previous time.
     *
     * @return the previous time
     */
    public double getPreviousTime() {
        return previousTime;
    }

    /**
     * Sets the previous time.
     *
     * @param previousTime the new previous time
     */
    protected void setPreviousTime(double previousTime) {
        this.previousTime = previousTime;
    }

    /**
     * Sets the current mips share.
     *
     * @param currentMipsShare the new current mips share
     */
    protected void setCurrentMipsShare(List<Double> currentMipsShare) {
        this.currentMipsShare = currentMipsShare;
    }

    /**
     * Gets the current mips share.
     *
     * @return the current mips share
     */
    public List<Double> getCurrentMipsShare() {
        return currentMipsShare;
    }

    /**
     * Gets the cloudlet waiting list.
     *
     * @param <T> the generic type
     * @return the cloudlet waiting list
     */
    @SuppressWarnings("unchecked")
    public <T extends ResCloudlet> List<T> getCloudletWaitingList() {
        return (List<T>) cloudletWaitingList;
    }

    /**
     * Cloudlet waiting list.
     *
     * @param <T>                 the generic type
     * @param cloudletWaitingList the cloudlet waiting list
     */
    protected <T extends ResCloudlet> void setCloudletWaitingList(List<T> cloudletWaitingList) {
        this.cloudletWaitingList = cloudletWaitingList;
    }

    /**
     * Gets the cloudlet exec list.
     *
     * @param <T> the generic type
     * @return the cloudlet exec list
     */
    @SuppressWarnings("unchecked")
    public <T extends ResCloudlet> List<T> getCloudletExecList() {
        return (List<T>) cloudletExecList;
    }

    /**
     * Sets the cloudlet exec list.
     *
     * @param <T>              the generic type
     * @param cloudletExecList the new cloudlet exec list
     */
    protected <T extends ResCloudlet> void setCloudletExecList(List<T> cloudletExecList) {
        this.cloudletExecList = cloudletExecList;
    }

    /**
     * Gets the cloudlet paused list.
     *
     * @param <T> the generic type
     * @return the cloudlet paused list
     */
    @SuppressWarnings("unchecked")
    public <T extends ResCloudlet> List<T> getCloudletPausedList() {
        return (List<T>) cloudletPausedList;
    }

    /**
     * Sets the cloudlet paused list.
     *
     * @param <T>                the generic type
     * @param cloudletPausedList the new cloudlet paused list
     */
    protected <T extends ResCloudlet> void setCloudletPausedList(List<T> cloudletPausedList) {
        this.cloudletPausedList = cloudletPausedList;
    }

    /**
     * Gets the cloudlet finished list.
     *
     * @param <T> the generic type
     * @return the cloudlet finished list
     */
    @SuppressWarnings("unchecked")
    public <T extends ResCloudlet> List<T> getCloudletFinishedList() {
        return (List<T>) cloudletFinishedList;
    }

    /**
     * Sets the cloudlet finished list.
     *
     * @param <T>                  the generic type
     * @param cloudletFinishedList the new cloudlet finished list
     */
    protected <T extends ResCloudlet> void setCloudletFinishedList(List<T> cloudletFinishedList) {
        this.cloudletFinishedList = cloudletFinishedList;
    }

    /**
     * Gets the cloudlet failed list.
     *
     * @param <T> the generic type
     * @return the cloudlet failed list.
     */
    @SuppressWarnings("unchecked")
    public <T extends ResCloudlet> List<T> getCloudletFailedList() {
        return (List<T>) cloudletFailedList;
    }

    /**
     * Sets the cloudlet failed list.
     *
     * @param <T>                the generic type
     * @param cloudletFailedList the new cloudlet failed list.
     */
    protected <T extends ResCloudlet> void setCloudletFailedList(List<T> cloudletFailedList) {
        this.cloudletFailedList = cloudletFailedList;
    }

}
